Weighing apparatus

Abstract

A weighing apparatus comprising a number of grippers each designed for receiving therein an object to be weighed, each gripper being mounted on a conveyor via a hingeless connection, so that the grippers are arranged for movement along a gripper path, each gripper comprising a first guide element which, over at least a part of the gripper path, moves over a weighing surface of at least one weighing element, the weight of the gripper and the object located therein being transferred vis the first guide element to the at least one weighing element, the hingeless connection between each gripper and the conveyor comprising at least one assembly of flexible members each having a particularly low spring constant in a direction perpendicular to the at least one weighing sruface.

What is claimed is:  
     
       1. A weighing apparatus comprising a number of grippers, each designed for receiving therein an object to be weighed, each gripper being mounted on a conveyor via a hingeless connection, so that the grippers are arranged for movement along a gripper path, each gripper including a first guide element which, over at least a part of the gripper path, moves over a weighing surface of at least one weighing element, the weight of the gripper and the object located therein being transferred via the first guide element to the at least one weighing element, wherein the hingeless connection between each gripper and the conveyor comprises at least one assembly of flexible members, each having a particularly low spring constant in a direction perpendicular to the at least one weighing surface. 
     
     
       2. A weighing apparatus according to  claim 1 , wherein the first guide element and the or each weighing element are arranged above an object received in the subject gripper. 
     
     
       3. A weighing apparatus according to  claim 1 , wherein one assembly of flexible members are arranged relative to the first guide element such that these members, at least when the first guide element moves over a said weighing surface, are all subject to tensile loading. 
     
     
       4. A weighing apparatus according to  claim 1 , including a second guide element and a reference guide over which the second guide element moves, at least when the first guide element moves over a said weighing surface, while a connection point between the conveyor and at least the flexible member located closest to the first guide element is displaceable in a direction perpendicular to the at least one weighing surface, the position of the displaceable connection point being controlled by cooperation of the second guide element and the reference guide, such that at least the or each flexile member provided with a displaceable connection point extends substantially parallel to the at least one weighing surface when the first guide element moves over a said weighing surface. 
     
     
       5. A weighing apparatus according to  claim 1 , wherein the connection between each gripper and the conveyor comprises a first and a second assembly of members, the weighing apparatus comprising a second guide element and a reference guide over which the second guide element moves, at least when the first guide element moves over a said weighing surface, the first assembly forming a connection between the second guide element and the conveyor, the second assembly forming a connection between the second guide element and the gripper, the members of the second assembly being flexible members each having a particularly low spring constant in a direction perpendicular to the weighing surface, the first and the second guide element and the at least one weighing surface and the reference guide being arranged relative to each other such that the flexible members of the second assembly extend substantially parallel to the at least one weighing surface when the first guide element moves over a said weighing surface. 
     
     
       6. A weighing apparatus according to  claim 5 , wherein the members of the first assembly are designed as flexible members having a particularly low spring constant in a direction perpendicular to the weighing surface. 
     
     
       7. A weighing apparatus according to  claim 5 , wherein the members of the first assembly are designed as rods having their ends pivotally connected to, on the one hand, the conveyor and, on the other, an intermediate piece which carries the second guide element. 
     
     
       8. A weighing apparatus according to  claim 1 , wherein the flexible members are flexible strips having a particularly high flexibility. 
     
     
       9. A weighing apparatus according to  claim 1 , wherein the flexible members are leaf springs. 
     
     
       10. A weighing apparatus according to  claim 1 , wherein each gripper, when the first guide element associated with the subject gripper does not move over the weighing surface, rests in a socket which is fixedly connected with the conveyor so that the load on the or each flexible member is removed. 
     
     
       11. A weighing apparatus according to  claim 10 , wherein each gripper comprises an operating lever and spring means, which spring means are biased to keep the gripper in a closed position, while, using the operating lever, the gripper can be opened against the spring force of the spring means, the socket in which a subject gripper rests being so designed so as to take up the reactive forces occurring upon operation of the operating lever. 
     
     
       12. A weighing apparatus according to  claim 1 , including a number of rows of grippers, which rows extend in a direction of transport, the apparatus comprising for each row of grippers at least one weighing element, designed as a weighing cell, comprising one weighing surface. 
     
     
       13. A weighing apparatus according to  claim 12 , including a number of rows of grippers, which rows extend in a direction of transport, the apparatus comprising for each row of grippers three weighing elements, designed as weighing cells, each comprising a weighing surface. 
     
     
       14. A weighing apparatus according to  claim 1 , including a processing unit which is connected to the or each weighing element and which is arranged for deriving from the signal generated by the or each weighing element a value related to the weight of the object.